To achieve a more efficient usage of memory, it is desirable that all different kinds of data structures require the same amount of memory from each level (layer). While this is not possible, the second best approach would be to ensure that a group of (say t instances) from a certain type of data structure uses a fixed amount of memory from each level. In fact, it would be even better if each group from each kind of structure occupies exactly the same amount of memory in each memory bank.
Thus, there is a demand to solve the problem with usage of memory of a multi-layered data structure.